So far as I have heard, they always said the breakup was due to Paul's insistence that Linda manage the band. Yoko was not the interfering sort- like Linda.

The Wall of Sound is the name some people gave to a super powerful, extremely accurate PA system that I designed and supervised the building of in 1973 for the Grateful Dead. It was a massive wall of speaker arrays set behind the musicians, which they themselves controlled without a front of house mixer. It did not need any delay towers to reach a distance of half a mile from the stage without degradation. It is not to be confused with the trademark overloaded-sound record mixes by that name made by Phil Spector for some Motown groups.